GPS接收机抗干扰空时自适应滤波方法

针对联合空时处理使计算量显著增加这一问题，本文研究一种数据分段输入的降秩自适应滤波方法，使GPS接收机空时抗干扰方法具有可行性和易行性。     

基于MATLAB数据采集系统的设计与实现

自然界中的许多物理信号都可通过传感器转换为电信号。与此同时,随着计算机软硬件技术以及电子技术的飞速发展,为更加准确、便捷地研究这些物理信号提供了基础。提出了一种数据采集、分析系统,给出了其软、硬件设计过程。该系统具有体积小、功耗低、电路结构简单、可靠等特点。     

Effects of periphery encapsulation material on the characteristics of micro vacuum dielectric capacitor

The effects of the periphery sealant on the electrical characteristics of vacuum dielectric capacitors (VDCs) are modeled. For the square shape VDCs, their characteristics are predominantly determined by the ratio of capacitor side length versus the width of boundary sealant layer, r. The smaller of the r value, the smaller of the dissipation factor, and the better frequency response of the VDCs are found. To achieve a dissipation factor of less than 10⁻⁵ at 1 GHz, the dimension parameter, r, should be smaller than 0.05 which has been achieved based on the present technology for a capacitor with size larger than 4 mm × 4 mm. The leakage current can also be reduced significantly in the VDCs. We found that the leakage current is mainly governed by the Poole-Frenkel emission of electrons over the periphery region. The present results have demonstrated that the VDC structure is a promising technology option for making high-frequency micro capacitors.     

相移迁移法在激光超声合成孔径聚焦技术中的应用

通过分析脉冲源激光辐照于工件表面激发的多模式、宽带超声体波信号并结合合成孔径聚焦技术(SAFT),实现了对工件内部微小缺陷的检测、定位和成像。首先基于有限元仿真模拟了激光激发超声波在含缺陷样品中的传播过程,编写了基于相移迁移法(PSM)的SAFT成像算法,然后在实验中使用激光在含缺陷样品表面激发超声波,使用激光测振仪探测超声波,并基于已有算法和探测结果对样品内缺陷进行了检测和定位,以验证算法的正确性。有限元仿真以及实验结果均表明,将激光超声技术与频域SAFT-PSM结合,能够有效地对微小缺陷进行检测和定位,且其图像重构速度快于时域SAFT,可为激光超声无损检测提供更快速的实时技术方案。     

一种基于薄膜体声波谐振器的高灵敏度质量传感器

介绍了一种针对于生物传感应用的薄膜体声波谐振(thin film bulk acoustic resonator,FBAR)质量传感器.薄膜体声波谐振器谐振频率非常高(能够达到几兆赫兹),同时具有较大的品质因数,基于这种器件的质量传感器具有非常高的质量灵敏度.首次提出了三对全金属的A1-W层作为布拉格声学反射层的FBAR,制备出了固态装配型的FBAR传感器.通过淀积不同厚度Al层顶电极分析了器件的质量灵敏度,仿真得到的质量传感器串联谐振频率在2.8 GHz附近,质量响应度达到5×10-4 ng/Hz//cm2,可以实现分子量级的质量传感.     

Multiuser beamforming based on max SINR for downlink spatial multiplexing MIMO

In this article, a method based on max signal interference noise ratio (SINR) criterion is proposed, to mitigate the interuser interference for downlink multiuser spatial multiplexing multi-input multi-output (MIMO) systems.Unlike the zero forcing (ZF) scheme in which the SNR is decreased when the interference is eliminated completely, max SINR method makes a compromise between noise and interuser interference.When the number of substreams is larger than the difference between the number of base station antennas and the sum of interference mobile station antennas, the ZF is infeasible.An existing coordinated TX-RX block diagonalization (COOR BD) method uses preprocessing at the receiver to cancel the interuser interference.However, it cannot obtain more receive diversity gain because of the preprocessing.Analysis and simulation show that the max SINR scheme has better performance than the ZF method.Moreover, when the ZF is infeasible, the max SINR scheme can obtain more receive diversity gain than COOR BD in the two-user case.     

移动IPv6概述

文章分析了IPV6支持移动性的优势，概述了移动IPv6协议，并对一些热点问题，如快速切换、平滑切换、移动管理、AAA和服务质量等进行了探讨。     

噪扰下数字化多频连续波雷达的测距模糊问题

数字化多频连续波测距雷达是一种新体制雷达.它具有能同时测定多个目标、便于同时得到目标多个运动参数等突出优点.为了解决增大最大测距不模糊距离与提高测距精度之间的矛盾,我们将会在多频雷达中采用参差频差关系进行测距,这样我们可以大大提高测距最大不模糊距离.但此时噪声对测距结果有着各种有待讨论的影响,包括:能否正确解模糊;对输入信号信噪比有何要求;理论测距精度有何变化;直至对参差系数有何要求等.数字化多频雷达的这些问题,本文对这些问题进行了详细的讨论,并给出了本文结论的计算机仿真结果.从而在理论上为这种雷达的深入研究提供了一个很好的基础.     

H原子在Si(111)-7×7表面吸附的STM研究

利用超高真空扫描隧道显微镜(UHV-STM),在液氮(78K)及液氦(4.2K)低温条件下研究了H/Si(111)-7×7吸附体系.H原子易于吸附在表面增原子(adatom)以及剩余原子(rest atom)的位置,导致表面局域电子态密度(LDOS)和STM图像发生明显的变化.利用扫描隧道谱技术(STS)测量获得了H吸...     

Service function chain embedding algorithm with wireless multicast in mobile edge computing network

To resolve the excessive system overhead and serious traffic congestion in user-oriented service function chain (SFC) embedding in mobile edge computing (MEC) networks,a content-oriented joint wireless multicast and SFC embedding algorithm was proposed for the multi-base station and multi-user edge networks with MEC servers.By involving four kinds of system overhead,including service flow,server function sustaining power,server function service power and wireless transmission power,an optimization model was proposed to jointly design SFC embedding with multicast beamforming.Firstly,with Lagrangian dual decomposition,the problem was decoupled into two independent subproblems,namely,SFC embedding and multicast beamforming.Secondly,with the L_p norm penalty term-based successive convex approximation algorithm,the integer programming-based SFC embedding problem was relaxed to an equivalent linear programming one.Finally,the non-convex beamforming optimization problem was transformed into a series of convex ones via the path following technique.Simulation results revealed that the proposed algorithm has good convergence,and is superior to both the optimal SFC embedding with unicasting and random SFC embedding with multicasting in terms of system overhead.